Evaluation and optimization of synthetic routes from dihydroartemisinin to the alkylamino-artemisinins artemiside and artemisone: A test of N-glycosylation methodologies on a lipophilic peroxide
作者:Wing Chi Chan、Dennis Ho Wai Chan、Kin Wo Lee、Wing Shan Tin、Ho Ning Wong、Richard K. Haynes
DOI:10.1016/j.tet.2018.04.027
日期:2018.9
N-glycosylation of DHA was examined but 2-deoxyartemisinin was invariably obtained. However, hydroxyl group activation by conversion into the 10β-halide in non-polar solvents with anhydrous HCl and Group I and II metal halides, oxalyl chloride or thionyl chloride with catalytic DMSO, and oxalyl bromide did succeed. The β-halides were converted in situ by thiomorpholine into artemiside, and by thiomorpholine-1,1-dioxide
包括青蒿素和青蒿素在内的10-烷基氨基青蒿素显示出增强的抗疟疾活性。早先,二氢青蒿素(DHA)TMS醚被三甲基甲硅烷基溴转化为10-β-溴化物,后者与胺亲核试剂一起提供了氨基青蒿素。为了开发更经济的方法,研究了DHA的直接N-糖基化,但是总是获得2-脱氧青蒿素。但是,在非极性溶剂中用无水HCl转化成10β-卤化物,并用催化DMSO催化的I和II类金属卤化物,草酰氯或亚硫酰氯,以及草酰溴的确使羟基活化。β-卤化物被原位转化通过硫吗啉转化成青蒿素,并通过硫吗啉-1,1-二氧化物转化成青蒿素。过氧化氢-乙腈或尿素-过氧化氢络合物将硫化青蒿素有效地氧化为砜青蒿素。总体而言,现在可以使用10-烷基氨基-青蒿素的通用方法。